AuthorTopic: New atmospheric model (Read 23795 times)

Well I have looked at these comparrison images carefully over a couple of days of re-visiting them, it seems to me that with the possible exception of the planetry horizon scaled shots (where the after is much better) there is not so much, an improvement as a change.... both 'before' and 'after' images represent possible realities because the atmosphere is so dynamic in reality. The main difference between before and after is the degree of haze (visible range) and once again this is a normal variable for a plenetry atmosphere that has thermo and flud dynamics in motion all of the time... Weather. I note that the contrast in terrain detail is lost or significantly reduced in the 'after' images which in my opinion is less attractive.BOTH SETS have great reality impact but if in acheving the 'afters' you must lose the possibility of the 'before' then this might be a backward step where the main benefit is in the accessability mentioned in your remarks. The final judgement will most likely require compromise.All in all this graphic still represents substancial improvements over any other simulator I have ever looked at.

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Yeah the comparison isn't saying enough about the change. The new atmospheric model mainly solved some corner cases that weren't rendered correctly (the night side, twilight transition) and also the perception of depth in some cases. It's also a bit faster and allowed for further optimizations as well as for a better further tuning of atmospheric parameters.

Additionally, the parameters weren't the same in both cases - their meaning changed and it was harder to match to the old ones. In the end there will be a UI window with sliders for adjusting the various atmospheric parameters.

Maybe,with Direct X 11 one can do this even better ,so you better incorporate it now ,if possible.I came to think about it ,can Vue 7 program maybe help in making a better reprensentation of season and maybe add to realism by adding parameters to make it simulate different road conditions-add a certain colour and it adds in a slippery road or something.Better find out what it can simulate without dragging down fps now,before we go too complex on weather model and everything else we can think of.Make sure of that it can manage the new whitepaper on the new MP Dis and HLA future systems,so that we can integrate the weather model into it.Hopefully we canuse Vue 7 system ,where one can `paint`their own clouds and overlays into the weather model,without the need of scripting or C++ programing .That will make it a whole lit easy for a lot of people.

You would not post your shaders here, would you? But for all of us, trying to get something similar working in our simulation software, a small technical blog post would be very appreciated! Because it looks just gorgeous...

I actually wanted to write a post about it, for the same reason I've been blogging about other technical things - to save myself and others the trouble of rediscovering it all again. But I missed that period when it has been fresh in my mind, so I have to go through it .. again

But I've been doing some fixes to the atmospheric code when toying with the water - I've encoded atmospheric parameters of reflected ocean ray into unused portion of precomputed textures. I've fixed some bugs during that encounter, but it's not yet all finished.

Btw the current incarnation of my atmospheric code was inspired by Eric Bruneton's atmospheric scattering algos, did you look at that? I've just simplified it a bit, reduced the inscatter table to be smaller and 3D instead of 4D, at the cost of having to recompute it from time to time. Basically doing some tradeoffs here and there.

Yepp, the work of Eric Bruneton is also very impressive. I read the papers but annoyingly the work on my visual software is only a side project at my office so I have to focus on getting everything in there but not in full detail

Last thing was volumetric clouds. But combining them with a complex atmospheric shader is some tough work. (At least for me... :/ )

So I am still looking (and hoping) for some ideas for a less complex atmospheric code...

Yes, the paper is not easy to understand without having a special training in the way these people write them

I hope I'll be able to write it in a more intelligible manner, but that will require even bigger effort than just dumping my notes and equations. Atmospheric code was one of the more annoying parts because of the amount of issues and tweaks required to get it right at all scales, and I still don't have it bug free.

Hell ya, thats right. I had this problem also. If the radians arent correct the sunset was too early or too late and it was looking unnatural. But i took nvidias gpu gem model. Thats physically "correct" but slower. So i'm also curious about your notes